Currently, cutting tools used to make a hole in a workpiece typically leave a sharp edge or burr at the entry-point of the cutting tool. This edge or burr is dulled or chamfered in a later cutting operation by another tool. This later cutting operation is inefficient and increases machining time to finish the workpiece.
Several forms of chamfering structures are known for mounting a chamfer cutter to a boring tool to reduce the number of cutting operations required to finish a workpiece. Art that has addressed this problem include U.S. Pat. No. 4,533,285 issued Aug. 6, 1985 to Charles A. Jorgensen for a Cutting Attachment For Boring Tool.
The broad purpose of the present invention is to provide a boring tool having an adjustable chamfering cartridge that is mounted along the outer edge of one of the chip flutes in tool. The boring tool having a cutting edge mounted to the lower end of an elongated shank and a chip flute running along the shank away from the cutting edge. The chamfering cartridge mates with an elongated rib that includes one wall of the chip flute.
The present invention overcomes the above-referenced and other disadvantages of prior art techniques by mounting an adjustable chamfering tool to a boring tool. The chamfering tool is compact enough to maintain a clear path for cutting chips to exit the boring tool and workpiece, while remaining rigidly mounted to the boring tool.
The present invention provides a combination boring and chamfering tool that can perform two machining operations in rapid succession (or simultaneously). The chamfering cartridge is slidably adjustable along the tool's chip flute permitting a user to cut various depth holes and still chamfer/deburr those holes with the same tool.
It is an advantage of the present invention to provide a boring tool having an elongated cylindrical shank, comprising at least one bore cutting portion mounted proximate to one end of the shank. Each cutting portion including a recessed chip flute formed in the shank and running away from the cutting portion. The tool further comprises a cartridge including a chamfer cutting portion mounted to a body. The body including means for mounting the cartridge to the shank where the cartridge is adjustably coupled to a single chip flute along the chip flute.
It is another advantage of the present invention to provide a boring tool, comprising an elongated cylindrical shank, an indexable cutting insert having a cutting face and is mounted to the shank proximate to a bottom end of the shank. The shank includes a recessed chip flute adjacent to the cutting insert. The flute runs longitudinally along the shank away from the cutting insert, wherein the flute includes a first wall that is generally collateral with the cutting face. The shank also includes an elongated mounting recess that runs longitudinally along the shank. The mounting recess including a second wall that is parallel, adjacent, and coextensive to the first wall, wherein the first and second walls cooperate to define an elongated rib. The tool further comprises a chamfer cutting cartridge having a body. The cartridge including an indexable chamfering insert and means for retaining the chamfering insert to the body. The body including a pair of spaced mounting lugs extending from the body. The lugs having opposed walls which define a channel, wherein this channel receives the rib such that the first wall and second wall each abut one of the opposed walls and the chamfering insert extends beyond the cutting insert radially.
It is still another advantage of the present invention to provide a method of adapting an indexable insert boring tool to also perform a chamfering operation, the boring tool having at least one cutting insert and a chip clearance flute running away from the cutting insert along a cylindrical shank. The method comprising the steps of: forming a mounting recess in and along the shank parallel and adjacent to the flute, wherein a portion of the shank remains between the flute and mounting recess to form an elongated rib; providing a cartridge having a chamfer cutter and a pair of spaced mounting lugs defining a channel; mating the cartridge to the shank by straddling the lugs over the rib; and adjusting the chamfering cartridge along the rib such that the chamfer cutter is a desired distance from the cutting insert.
It is yet another advantage of the present invention that the chamfering cartridge abuts the shank along substantially all of the shank facing surfaces, this abutting engagement prevents cutting debris, such as chips, from jamming in the boring tool.
Still further objects and advantages of the invention will become readily apparent to those skilled in the art to which the invention pertains upon reference to the following detailed description.